Q: I have a 1996 Grand Marquis with 56,000 miles and a nearly-new battery. I turned the ignition switch, the engine cranked beautifully, then died (I have had this problem for a while because the car is not driven much and the fuel injectors need cleaning). No big deal. I turned the ignition switsh again, and in less than a second, everything was dead. The dash lights went out, the headlights were dead, and I could not unlock the door by remote or keyless pad on door. I heard a fast clicking inside the light switch. I recharged the battery. The lights were bright, everything worked. I turned the ignigion switch, and in less than a second, everything was dead. I recharged the battery again, left the charger attached to the battery for an added boost, turned the ignition switch and in less than a second the battery was completely dead, and my battery charger was dead as well.

I talked to the service rep at my dealership and he said he thought this all happened because the battery was just a bit under 12 volts when i tried to crank the car. (Say what?!?!?) Needless to say, I don't want them coming out to work on the car.

A: Trust me, you're not discharging a fully-charged car battery in a second or two. That would release enough energy—as heat—to make the engine block glow red-hot and probably make the battery explode.

You've got a high-resistance connection somewhere between the battery and the starter motor, either in the positive or negative battery cable. And it's probably corrosion at the clamp. The high resistance will pass enough current to run the dash lights and the starter solenoid (10 amps or so), but when the starter motor kicks in, the huge current draw (200-300 amps) drops the battery voltage way too low to light up anything. At the same time the localized heat in the bad connection blows out the very small contact area in the clamp or cable that's been carrying what little current has been sneaking past. Now you have a very high-resistance connection, one that's too poor to even light up the dash.

Attaching jumper cables or the battery charger then disturbs the connection enough to reestablish a better, but still inadequate, connection, at least until you try to start the car again. You can check with a voltmeter or even a test light for voltage drop along the starter wiring. There should be less than a half a volt of voltage drop across any connection.

But I'd just start by removing and cleaning up the battery posts and clamps. If they're fine, follow the big positive lead to the starter solenoid. Don't forget to check the negative lead, which connects to both the engine block and the car frame.

I further would guess your battery charger isn't really blown. It's trying to charge the battery across that high-resistance connection, because you're probably attaching the charger's alligator clips to the clamp, not directly to the battery post.

And yes, this is typical for a car that isn't used regularly. Once you've cleaned everything up and got the car started. The service rep obviously doesn't comprehend how the starting system and battery work. Let's hope the the service technicians who work on vehicles at this dealer remember some of their 8th grade physics.

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